Keith, it would be helpful for this, and future posts if you were to put your RV year, make and model in the signature line in your profile for us.
On my unit, the gas line pipe hangs on the frame, and was already plumbed for an external grille, so I just swapped the fitting and regulator on my Blackstone for a female quick-connect gas fitting.
When I got my unit (used, private party) my quick-connect valve had a slight leak, so I replaced it. They are readily available at the RV stores, and come in a kit with both the male and female end. It is a type that looks like a male air quick connect fitting, except it has a safety valve in the form of a lever, which locks the female end from the grille to it.
My unit uses conventional threaded 1/2" black gas pipe. If you have any gas appliances, just `T' into the line at the nearest point where you want your grille to attach. Be sure to check for leaks before using it, with soapy water.

The simplest is to buy a "Y" for your propane bottle, if it's exposed, then have your local LP dealer make up a hose to whatever length you want. If the grill has a regulator this setup works great, if it doesn't you may need one on the hose. If you plumb into the line near another of the appliances you will need to remove the regulator from the grill if equipped.
My 5er had the bottle on the curbside, I used the Y & had a 25' hose made so I can place the grill anywhere I want, works great. Buying the parts at the LP dealer is usually cheaper than at at a rv dealer & you can get exactly what you want.